Abrading apparatus for use in well bores



Sept. 19, 1967 w. WOODS 3,342,270

ABRADING APPARATUS FOR USE IN WELL BORES Filed Aug. 25, 1965 2 Sheets-Sheet 1 INVENTOR JOHN W. WOODS BY M, Dom, M MK ATTORNEY! Sept. 19, 1967 Filed Aug. 25, 1965 FIGZ J. W. WOODS ABRADING APPARATUS FOR USE IN WELL BORES 2 Sheets-Sheet INVENTOR JOHN W. WOODS BY 0%, Ma Marywmg ATTORNEYS United States Patent Office 3,342,270 ABRADING APPARATUS FOR USE IN WELL BORES John W. Woods, Duncan, kla., assignor to Halliburton Company, Duncan, Okla, a corporation of Delaware Filed Aug. 25, 1965, Ser. No. 482,556 9 Claims. (Cl. 166-173) ABSTRACT OF THE DISCLOSURE A well abrading tool including a generally cylindrical body and a plurality of elongate abrading members projecting from the outer periphery of this body. Each elongate member includes a plurality of protrusions which project generally laterally of the member and have a common median plane when the member is unstressed. Each such elongate member also has a free end engageable with material on a well wall into which the abrading tool is inserted. The elongate members are mounted on the cylindrical body so that each member extends generally transversely of the body, with the free end of each member and at least some of its protrusions being mutually spaced generally transversely of the body. The free end and at least one of the protrusions of each elongate member are concurrently, abradingly engageable, with material on the wall of the well into which the tool is inserted.

General background of invention This invention pertains to an abrading apparatus for use in well bores. In particular, it relates to a well bore scratcher adapted to be reciprocated axially of a well bore.

The drilling and completion of wells, such as oil, gas or water wells, frequently entails the cementing of well liners to a formation. In order to provide an effective bond between well cement and a formation wall, it frequently is desirable to abrade the formation face so as to remove foreign material. Such material usually comprises caked sediment from drilling fluids such as drilling mud.

A variety of well wall scratching, i.e. abrading devices, have been developed. However, in general these devices have been characterized by structural complexity which made their assembly, maintenance and repair diflicult or cumbersome. In addition, such devices have often been excessively vulnerable to damage during abrading operations.

It has also been noted that in many instances where wire-like abrading elements have been employed, the abrading action of these elements has been confined to their outer extremities.

Objects and summary of invention It is an object of the present invention to provide an improved abrading apparatus for use in a well bore which substantially overcomes or minimizes problems of the type heretofore noted.

It is a principal object of the present invention to provide an improved abrading element structure for use in a Well bore. This improved structure, which finds particular utility in relatively small well bores, provides a significant increase in the overall extent of abrading action to remove unwanted material from the wall of a well bore.

It is a particular object of the invention to provide such an improved apparatus which is characterized by a minimal number of components which may be conveniently and rapidly assembled even by relatively unskilled personnel.

Patented Sept. 19, 1967 It is a related object of the invention to provide such an improved apparatus containing components which may be secured without resorting to separate holding elements, clips, etc. and which may be assembled by relatively simple tools.

It is also an object of the invention to provide such improved apparatus which includes abrading elements as above described each comprising a plurality of well well abrading fingers with plural abrading protrusions, which fingers are so mounted upon associated body means as to provide resilent means tending to resilently impede the transmittal of force from one finger to another.

A still further object of the invention is to provide such an apparatus wherein radially inwardly directed force imposed upon the abrading apparatus in use in a well bore will tend to intensify the securing of abrading elements to associated body means while abrading finger protrusions tend to cushion the imposed force.

Yet another object of the invention is to provide such an apparatus wherein securing means which tend to aifix abrading elements to associated body means project radially outwardly beyond the body means so as to provide resilient abutments tending to protect the body means and its associated structure from radially inwardly apparatus against laterally directed forces.

It is also an object of the invention to provide such an improved abrading apparatus wherein securing means resiliently urge abrading elements into engagement with associated body means so as to maintain an effective, abrading element securing action.

Yet another object of the invention is to provide an improved apparatus which is characterized by overall structural simplicity, but operational ruggedness and dependability.

In accomplishing the objects of the invention relating to the obtaining of an improved abrading action within a well bore, there is provided an improved abrading element which comprises an elongate member having a plurality of protrusions projecting laterally thereof. These protrusions have a common median plane when the member is substantially unstressed. A free end of the member is adapted to engage material on a well bore.

Individual significance is attached to a preferred form of the above-noted protrusions. In this preferred form. a plurality of generally arcuate protrusions project generally laterally of the elongate member in one direction and a plurality of generally V-shaped protrusions project laterally of the member in a direction generally opposite to the one direction. The arcuate protrusions alternate with the V-shaped protrusions longitudinally along the member.

In further accomplishing the foregoing objects, there is provided through this invention an overall abrading apparatus for use in a well bore, which apparatus comprises body means and securing means for holding the body means on the outer periphery of conduit means.

, means thereof disposed at least in part on one side of the body means and the abutment means thereof disposed on an opposite side of the body means. The resilient means extends at least in part through at least a portion of the aperture means. The resilient means has a portion larger than this aperture means portion on said one side 3f said body means in a direction extending transversely 3f the aperture means portion. This larger portion of the resilient means is yieldably and resiliently contractable so as to be movable through said aperture means portion.

A particularly efficacious combination intended to accomplish several of the foregoing objects relates to the overall abrading apparatus as above described provided with abrading elements having a plurality of laterally projecting protrusions as above noted.

An independently significant aspect of the invention involves the structure of individual abrading elements as heretofore described in combination with a contractable loop structure which provides said resilient means.

Drawings In describing the invention reference will be made to a preferred embodiment illustrated in the appended drawings.

In the drawings:

FIGURE 1 is a fragmentary, elevation view of a portion of a conduit string upon which an abrading apparatus of this invention is mounted;

FIGURE 2 is a plan view of the assembly shown in FIGURE 1;

FIGURE 3 is an enlarged, sectional and elevational view of a portion of the FIGURE 1 assembly as viewed along the section line 33 of FIGURE 2;

FIGURE 4 is a fragmentary, sectional view of a portion of the FIGURE 1 assembly as viewed along the view direction 44 of FIGURE 1;

FIGURE 5 is an enlarged. elevational view of an individual abrading element incorporated in the FIGURE 1 assembly; and

FIGURE 6 is a schematic, fragmentary, transverse, cross sectional view of the abrading apparatus of FIG- URE 1 disposed within a well bore and illustrating the manner in which abrading fingers are deflected into multipoint abrading contact with material to be removed from a well bore.

FIGURE 1 illustrates a portion of conventional well conduit means such as a casing or tubing string 1 upon which an abrading apparatus 2, Le. a well scratcher, is mounted.

As will be appreciated, a plurality of well scratchers 2 may be supported upon conduit string 1 and axially spaced along this string.

Well scratcher 2 includes, as its major components, body means 3 and abrading elements 4.

As shown in FIGURES 1 and 2, abrading elements 4 are mounted upon body means 3 so as to be generally uniformly and circumferentially spaced around conduit string 1.

Body means 3 is fabricated from two or more arcuate, collar-like segments. As shown in FIGURE 2, semi- -:ylindrical collar segments 5 and 6 are interconnected by conventional strip hinge units 7 and 8.

Body segments 5 and 6 may be permanently connected by hinge 7, with hinge 8 providing a selectively releasable coupling. Thus, as shown in FIGURES l and 2, aligned hinge sections 8a and 8b may be interconnected by a hinge pin 8c. This hinge pin may include an abutment 8d to prevent the pin So from moving downwardly out of the aligned openings of the interconnected hinge sections 8a and 812.

With the hinge connecting arrangement shown in FIG- URES 1 and 2, body segments 5 and 6 may be closed in coaxial encircling engagement around conduit string 1 and be secured in position by the insertion of hinge .pin 80.

In describing the relationship between abrading elements 4, the body means 2, and the conduit means 1, reference will often be made only to the representative body segment 6. It will be understood, however, that references made in connection with the body segment 6 are equally applicable to corresponding structure associated with the body segment 5.

Each body segment has a vertical cross-section as generally shown in FIGURES 1 and 3 including a recessed portion which, in cooperation with the conduit string 1, defines a space between the body segment and the outer periphery 1a of the conduit string 1. Thus, as shown in FIGURE 3, the body segment 6 includes a recessed portion 6a which provides a generally semicylindrical cavity 9 disposed between the outer periphery 1a of the conduit string 1 and the inner wall portion 6b of the portion 6a of the body segment 6.

Wedge means may be provided to enact with the body segments 5 and 6 and the outer periphery 1a of the conduit means 1 so as to positively secure the assembled body means 2 in a fixed position on the conduit string 1.

As shown in FIGURE 1, the wedge means may comprise generally semi-conical wall portions 60 and 6a! in the lower portion of body segment 6. As illustrated in FIGURES 1 and 4, wall portions 60 and 6d slope progressively radially outwardly in a direction toward segment openings 6e and 6 respectively. As shown, a segment opening 6g extends between and connects openings 6e and 6 A segment wall 6 h in which opening 6 g is formed and from which wall portions 60 and 6d are deflected is substantially contiguous with conduit string periphery 1a in the assembly shown in FIGURES 1 and 4. Wedge means such as conventional cement nails, which may have spirally grooved outer peripheries, may be inserted into the openings 6e and 6 and wedged between the Wall portions 6c and 6d and the outer periphery 1a of the conduit string to tightly wedge the body means in a fixed position on the conduit means 1, restrained against either axial or rotary movement. Thus, as shown in FIGURE 4, wedging nails 10 and 11 have been inserted into the body segment openings 62 and 6] so as to be wedged, respectively, between the segment wall 60 and the conduit periphery 1a and between the segment wall 6d and the conduit periphery 1a. A similar wedging arrangement, not shown, may be utilized in conjunction with the other body segment 5.

As shown in FIGURE 5, each abrading element is fabricated as a unitary resilient, wire-like member. Each abrading element would ordinarily be fabricated of spring steel wire. As will be apparent by reference to FIGURE 1, the representative abrading element 4 shown in FIGURE 5 is disposed in substantially the same elevational position as it occupies in the assembly of FIGURE 1.

Each abrading element 4 as shown in FIGURE 5 includes paired abrading fingers 12 and 13 which provide well wall or well surface abrading means.

A generally helical loop portion 14 provides resilient fastening and stress releasing means in each abrading element 4. Essentially linear, abutment defining, connecting portions 15 and 16 extend in generally opposite directions away from the loop portion 14. In the FIGURE 1 assembly, connecting portion 15 extends from the lower side 14a of the loop portion 14 generally upwardly away from the loop portion 14. Connecting portion 16 extends generally downwardly from the upper portion 14b of loop portion 14. Loop portions 14a and 14b cross and preferably are contiguous at the base of the loop 14 where they merge into the connecting portions 15 and 16.

The looping axis 14c of the loop portion 14 extends generally transversely of the linear axes 15a and 16a of the connecting portions 15 and 16, respectively. Thus, an axial force exerted on either connecting portion in a direction away from the loop portion 14 will tend to cause resilient tightening or contraction of the loop portion 14.

A helical coil 17 connects finger 13 with connecting portion 15 while another helical coil 18 serves to connect finger 12 with connection portion 16.

Finger 13 includes a base portion 13a which extends from the helical coil 17 and an outermost, deflected, well wall engaging end 13b. Similarly, finger 12 includes a base portion 12a extending from coil 18 and a deflected, well wall engaging free end 12b. As shown with reference to FIGURE 2, finger portions 12b and 13b are deflected upwardly with reference to a well bore installation such that their linear axes are generally coplanar with planes extending through the linear axes of intermediate finger portions 12c and 13c, respectively, and are parallel with a common central axis of the conduit means 1 and the assembled body means 3.

As noted, abrading elements 4 include fingers 12 and 13. These fingers are substantially identical, may 'be viewed as individual abrading members even though integral portions of a composite element, and are provided with laterally projecting protrussions of a substantially identical character. Thus, in describing these protrusions reference will be made to exemplary protrusions on a finger 13. In so doing it will be appreciated that the abrading fingers or elements 12 are configured in the same manner as the fingers 13.

Each finger 13 is provided with a plurality of protrusions 1301 extending generally longitudinally of the finger. As shown in FIGURE 5, when the fingers of a representative abrading element 4 are disposed in an unstressed or natural condition, i.e. the condition preceding the insertion of the apparatus into a well bore which would cause flexing or stressing of the fingers, the protrusions 1301 have a common median plane P.

The free end 13b of the finger 13 which is adapted to engage material on a well bore wall to be abraded or removed therefrom is inclined relative to the median plane P.

As will be apparent by reference to FIGURES 1, 2, 3 and 5, the median plane P is inclined to and extends generally transversely of the central axis A of the supporting conduit 1. Thus, the protrusions 1301 project generally laterally relative to the axis A. As will also be apparent by reference to the drawings, the inclination of the free finger ends 13b and 12b is such that they are aligned with planes extending generally tangentially of the annular body means 3.

In the preferred and illustrated embodiment the protrusions 1301 comprise alternating generally arcuate and generally V-shaped protrusions. Thus, as is shown in FIGURE 3, a plurality of generally arcuate protrusions 1302 project generally laterally outwardly of the conduit axis A and the finger 13. A plurality of generally V- shaped protrusions 1303 project generally laterally inwardly of the finger 13 toward the conduit axis A. As illustrated, the arcuate protrusions 1302 alternate with the V-shaped protrusions 1303 longitudinally along the fingers 13, with an arcuate protrusion 1302 being disposed immediately adjacent the free finger end 13b.

FIGURE 6 illustrates the mode of engagement of the fingers 12 and 13 with material in caked or deposited on the wall W of a well 'bore. Wall W conventionally would comprise well casing. Material M may comprise caked mud deposited from drilling fluids or other sediment which is desired to be removed from the well wall W.

As shown in FIGURE 6, the free finger ends 13b are disposed in engagement with the material M. As illustrated, many of these fingers 13b are disposed in generally flush engagement with the radially inner peripheral surface of the material M.

As is also shown in FIGURE 6, several arcuate finger protrusions 1302 are also in engagement with the mate rial M. The median plane of these protrusions is generally inclined relative to the axis A such that the protrusions 1302 engage the material M in a generally sloping and shovel-like fashion. These protrusions 1302 are generally maintained in a generally planar configuration.

As illustrated, the coil axis 17a of helical coil 17 and the coil axis 18a of helical coil 18 extend generally transversely of the linear axes of the fingers 12 and 13 and the loop axis 14c. As is further apparent by reference -to FIGURE 3, the base 13a of the finger 13 adjacent the 6 coil 17 and the base 12a of the finger 12 adjacent the coi 18 are disposed in substantially flush relationship wit] the adjacent outer periphery of the body means 3 whet the individual scratcher 4 is assembled for use as showr in FIGURE 1. Further, the finger base portions 13 and 12a are radially disposed between the radially outwan extremity 14d of the loop portion 14 and the outer periphery 1a of the conduit means 1 when the abrading element 4 is mounted as shown in FIGURES 1 and 3 Each body segment 5 and 6 is provided with a plurality of aperture groupings 19. Aperture groupings 19 are circumferentially spaced about the conduit means 3 when the body means 2 is secured thereon in the assembled position shown in FIGURE 1. Each such grouping comprises three circular apertures 20, 21 and 22 which are spaced along an axis generally parallel with the central, com mon axis of the body means 3 and the conduit means 1. As illustrated in connection with the body segment 6, the apertures 20, 21 and 22 are formed in the recessed body segment portions such as the portion 6a of the segment 6. These apertures comprise means for mounting the abrading elements in a fashion which will now be decribed.

Each abrading element is mounted on the body means 3 so that its resilient loop portion 14 has the major portion thereof disposed on the radially outward side of the body means 3. Thus, as shown in FIGURE 3, the loop portion 14 of the abrading element 4 has its major portion, including the outer extremity 14d, positioned on the radially outward side 6c of the segment 6.

The abutment defining connecting means of each abrading element are disposed on the radially inward side of the body means 3 so as to be located between the body means and the outer periphery 1a of the conduit means 1. Thus, as shown in FIGURE 3, the abutment defining connecting portions 15 and 16 are disposed between the inner wall 6:: of the body segment 6 and the outer periphery 1a of the conduit string 1.

As shown in connection with FIGURE 3, each resilient means defining loop 14 projects generally radially outwardly from the common central axis of the conduit string 1 and the assembled body means 3 and projects at least in part through a central aperture 21. The outer diameter d of the loop portion 14, in the relaxed, i.e. unstressed, condition of the loop 14, exceeds the diameter of the circular aperture 21. Thus, the loop 14 is larger in a dimension extending transversely of the aperture 21 than the portion of the aperture 21 through which it extends. However, the loop portion 14 is yieldably and resiliently contractable, owing to the spring-like character of the material from which the element 4 is fabricated, so as to enable the loop 14 to be drawn or snapped through the aperture 21. Thus, when the abrading apparatus is being initially assembled and before it is mounted on the conduit string 1, hook-like tools may be inserted through the apertures 21 and engaged with loop elements 14 and drawn back through the apertures 21 so as to move the loops to the representative position shown in FIGURE 3. In this position, the loop has re-expanded and the loop portions 14s and 14 are engageable or engaged with generally diametrically opposite edge portions 21a and 21b of the central aperture 10. This loop expansion may take place with the loop portion 14 not being allowed to assume its fully relaxed condition. In this event, the engagement of the loop base portions 142 and 14f with the aperture edges 21a and 21b, prior to full loop enlargement, will resiliently cam the loop 14 radially outwardly so as to resiliently urge the connecting portions 15 and 16 into abutting engagement with the inner surface 6a of the body segment 6. In any event, the loop 14 will be engageable with the segment outer periphery 60 so as to secure the element 4, with the loop 14 and the connecting portions 15 and 16 functioning as securing abutments disposed on opposite sides of the segment 6.

As illustrated in FIGURE 3, in connection with repreentative abrading element 4, connecting portion 15 exends generally toward the uppermost aperture 20- while .onnecting portion 16 extends generally toward the lowernost aperture 22. Helical coil 17, which interconnects onnecting portion 15 and finger 13 is disposed in gen- :rally radial alignment with circular aperture 20 with he finger 13 projecting generally outwardly and angularly way from the aperture 29. Similarly, the helical coil aortion 18 which interconnects connecting portion 16 and inger 12 is disposed in generally radial alignment with be circular aperture 22 with the finger 12 projecting generally outwardly and angularly away from this aperzure. As shown, the coils 17 and 18 may be somewhat smaller in diameter than the apertures 20 and 22 so as to be freely nested in the apertures 20 and 22.

With the apparatus assembled as shown in FIGURES 1 and 2, coil portions 17 and 18 have their coil axes 17a and 18a extending generally radially of the conduit means 1 and body means 2. With the loop 14 of an element 4 engaging the edges of the aperture 21, the radial alignment, i.e. centering, of the coil portions of the abrading element and their associated apertures is automatically facilitated.

As illustrated in FIGURES 2 and 3, the fingers 12 and 13 may be inclined at different angles with respect to the radial axes of their respectively associated apertures 22 and 20.

Abrading fingers 12 and 13, of course, will be of such length as to terminate on the periphery of a circle having a radius exceeding that of a well bore portion to be abraded.

The resilient loop portions 14 of the abrading elements 4 project radially outwardly beyond the radially outermost extremities of the body segments 5 and 6, the hinges 7 and 8, the wedging nails 10 and 11 and the coils 17 and 18 as generally shown in FIGURES 2 and 3.

As will be appreciated, with the generally radially projecting character of the loops 14, a force directed radially inwardly of the scratcher will tend to flatten and thus transversely enlarge the loops 14 with reference to the mounting aperture 21. In this connection, it should be noted that in the illustrated embodiment, the width of the space 9 is sufficiently narrow as to positively insure that the base of the loop 14 and the abutment portions 15 and 16 will engage the conduit periphery It: so as to prevent the loop from being pushed through the aperture 21 in response to such an applied force.

With a conduit string provided with one or more abrading essemblies such as that shown in FIGURE 1 and positioned in a well bore, vertical reciprocation of the conduit string will cause the abrading fingers to engage and scratch and abrade a formation face. This abrading action is facilitated by the springy character of the abrading fingers.

The axial reciprocating action of the conduit 1 will cause arcuate protrusions of the abrading fingers and the free ends formed on these fingers to effectively scrape a well wall so as to remove deposited material such as mud cake.

The overall effectiveness of the abrading action is materially improved by me multi-point contact of most of the abrading fingers, i.e. cont-act by the free end and at least one protrusion of each finger.

With the structure and mode of operation of the abrading apparatus having been described, several advantages of the invention have been made apparent.

The protrusions formed integrally in the abrading finger elements provide an abrading action of particular effectiveness. Multiple point contact between material to be abraded and a free end and one or more protrusions of each finger provides a more even and extensive distribution of the material removing action of the reciprocating fingers.

As will be appreciated, the abrading action of the fingers and their associated protrusions is augmented in inverse proportion to the size of a well into which the apparatus is inserted. The smaller the diameter of the well wall, the greater will be the flexing or bending of the fingers 12 and 13. Increased flexing of the fingers, of course, will serve to place more protrusions in abrading engagement with material to be removed from a well wall.

The inclined and generally planar disposition of the individual protrusions relative to the conduit axis and thus also the well wall, imparts to the reciprocating protrusions a shovel or wedge type of action. This action, of course, serves to particularly effectively remove material from the well wall. This inclination also tends to cushion the apparatus against lateral crushing forces by providing resilient abutments.

With the free finger ends being inclined relative to the common median plane of the unstressed fingers, and with this free end being in generally flush engagement with material on a well wall, the protrusions are stabilized in their inclined disposition. Thus, the protrusions tend to be stabilized during the reciprocating action of the supporting conduit so as to maintain the protrusions in a disposition to effect the efficient removal of material from the well wall.

The alternating use of outwardly facing arcuat-e protrusions and inwardly facing V-shaped protrusions in and of itself is significant. The arcuate shape of the abrading protrusions minimizes finger wear during operation and provides a maximized abrading surface. The V-shaped protrusions minimize the spacing between the arcuate protrusions so as to further increase the numbers of armate protrusions likely to be in contact with material to be removed from a well wall.

While abrading is taking place, it is possible for individual fingers to be subjected to an outward pulling force when they become engaged or caught on well bore portions. Should such pulling result on an individual finger, the pulling force, if sufficient, may be transmitted through the connecting portion associated with the finger to the loop 14 of the abrading element. This force will tend to cause resilient contraction of the loop 14. This contraction may advantageously prevent the transmission of finger-damaging force to the other finger of the abrading element 4.

During abrading operations or while a conduit string is being lowered or raised in a well bore, the abrading assembly may be forced against adjacent well bore portions. Should such contact occur, a radially inwardly directed force will be imposed against the outermost radial extremity of the assembly at the contact point. As previously noted, this outermost extremity will comprise one or more loops 14 depending upon the circumferential extent of the contact. When such contact occurs, the contacted loops 14 will tend to flatten so as to improve their holding action. In addition, their resilience may be such as to prevent the transmission of crushing or damaging force to other portions of the abrading apparatus including body segments, connecting hinges, wedge pins, helical coils, etc.

The transverse direction and resilient protrusion 1301 also provide resilient, abutment-like means tending to further cushion the abrading apparatus against lateral crushing forces.

The resilient engagement of the loop 14 with the aperture 21 provides a resilient or biasing type of holding action tending to securely hold the abrading elements in engagement with their associated body segments, and additionally, automatically centers the coils 17 and 18 in relation to their apertures 20 and 22. This resilient holding action may tend to prevent wear and damage which would result from an excessively loosely mounted finger element.

The use of the loop 14 and the apertured body segments provides a uniquely simplified abrading apparatus assembly involving a minimum number of parts and minimized and simplified fabrication techniques. Assembly of the apparatus elements 4 and the body segments is accomplished by merely snapping, i.e. pulling, the loops 14 through the apertures 21. This arrangement, of course, facilitates the assembly of the apparatus.

In describing the invention, reference has been made to a preferred and highly advantageous embodiment. However, those skilled in the well cleaning or well wall abrading art and familiar with the disclosure of this invention may envision additions, deletions, substitutions or other modifications which would fall within the purview of the invention as defined in the appended claims.

I claim:

1. In combination:

a well;

conduit means supported for axially reciprocable movement within said well; and

well wall abrading means supported by said conduit means, said abrading means comprising a plurality of abrading elements projecting from said conduit means into engagement with material on an interior surface of said well, each said abrading element comprising an elongate member;

a plurality of protrusions projecting generally laterally of said member;

said protrusions having a common median plane when said member is substantially unstressed; and

a free end adapted to engage material on a well wall;

the free ends of said abrading elements and at least one protrusion of each abrading element being in engagement with said material.

2. A combination as described in claim 1 wherein the protrusions of at least one of said members comprise:

a plurality of generally arcuate protrusions projecting laterally of said one member in one direction; and

a plurality of generally V-shaped protrusions projecting laterally of said one member in a direction generally opposite to said one direction;

said generally arcuate protrusions alternating with said generally V-shaped protrusions longitudinally along said member; and

wherein said member comprises a length of resilient wire, with said protrusions comprising portions of said length.

3. A combination as described in claim 2 wherein the free ends of at least some of said elements are inclined relative to the common median plane of the protrusions of said elements and are disposed in generally flush engagement with said material.

4. A combination as described in claim 3 wherein at least some of the protrusions of said abrading elements engage said material and are inclined relative to said well wall.

5. An abrading apparatus for use in a well bore, said apparatus comprising:

body means;

securing means for holding said body means on the outer periphery of conduit means;

said body means having portions defining aperture means;

at least one abrading element comprising flexible, surface abrading means comprising at least one elongate portion,

a plurality of protrusions projecting generally laterally of each said elongate portion;

said protrusions of each said elongate portion having a common median plane when said portion is substantially unstressed;

each said elongate portion having a free end adapted to engage material on a well wall,

resilient means, and

abutment means extending from said resilient means and connected with said surface abrading means; said abrading element being mounted on said body 5 means with said resilient means extending at least in part through at least a portion of said aperture means, and having a portion larger than said aperture means portion on said one side of said body means in a direction extending transversely of said aperture means portion, with said larger portion of said resilient means being yieldably and resiliently contractable so as to be movable through said aperture means portion.

6. An abrading apparatus as described in claim 5 wherein said protrusions associated with each elongate portion comprise:

a plurality of generally arcuate protrusions projecting laterally of their associated elongate portion in one direction; and

a plurality of generally V-shaped protrusions projecting laterally of their associated elongate portion in a direction generally opposite to said one direction;

said generally arcuate protrusions alternating with said generally V-shaped protrusions longitudinally along said associated elongate portion; and

wherein each said elongate portion comprises a length of resilient wire, with said protrusions comprising portions of said length.

7. An abrading apparatus as described in claim 6 wherein said free end of each elongate portion is inclined relative to the common median plane of the protrusions of said elongate portion.

8. An improved abrading tool for use in a well bore, said abrading tool comprising:

a generally cylindrical body means;

a plurality of elongate members mounted on said body means,

a plurality of protrusions projecting generally laterally of each said elongate member and having a common median plane inclined relative to the longitudinal axis of said body means when said member is substantially unstressed;

each said elongate member having a free end adapted to engage material on the wall of a well into which said tool is inserted; and

means mounting each elongate member on said body means such that each such member extends generally transversely of the outer periphery of said body means, with the free end and at least some of the protrusions of each such member being mutually spaced generally transversely of said body means, and with at least the free end and one of said protrusions of at least some of said elongate members being concurrently engageable with material on the wall of a well into which said tool is inserted.

9. An improved abrading element for use in a well 50 bore, said abrading element comprising:

an elongate member; a plurality of protrusions projecting generally laterally of said member, said protrusions comprising a plurality of generally arcuate protrusions projecting laterally of said member in one direction, and a plurality of generally V-shaped protrusions projecting laterally of said member in a direction generally opposite to said one direction, said generally arcuate protrusions alternating with said generally V-shaped protrusions longitudinally along said member; said protrusions having a common median plane when said member is substantially unstressed; and a free end adapted to engage material on a well wall;

11" said elongate member comprising a length of resilient 2,584,634 wire with said protrusions comprising portions of 2,812,531 said length. 2,832,420 2,888,989 References Cited 5 3 30 3 64 UNITED STATES PATENTS 2,421,434 6/1947 Reistle et a1. 166-173 2,454,884 11/1948 Peaden 15-104.3 X

12 Spang 15-104.1 X Ashley 15104.16 X Breukelman 166173 Park 166-173 Owsley 166-173 CHARLES E. OCONNELL, Primary Examiner.

DAVID H. BROWN, Examiner. 

1. IN COMBINATION: A WELL; CONDUCIT MEANS SUPPORTED FOR AXIALLY RECIPROCABLE MOVEMENT WITHIN SAID WELL; AND WELL WALL ABRADING MEANS SUPPORTED BY SAID CONDUIT MEANS, SAID ABRADING MEANS COMPRISING A PLURALITY OF ABRADING ELEMENTS PROJECTING FROM SAID CONDUIT MEANS INTO ENGAGEMENT WITH MATERIAL ON AN INTERIOR SURFACE OF SAID WELL, EACH SAID ABRADING ELEMENT COMPRISING AN ELONGATE MEMBER; A PLURALITY OF PROTRUSIONS PROJECTING GENERALLY LATERALLY OF SAID MEMBER; SAID PROTRUSIONS HAVING A COMMON MEDIAN PLANE WHEN SAID MEMBER IS SUBSTANTIALLY UNSTRESSED; AND A FREE END ADAPTED TO ENGAGE MATERIAL ON A WELL WALL; THE FREE ENDS OF SAID ABRADING ELEMENTS AND AT LEAST ONE PROTRUSION OF EACH ABRADING ELEMENT BEING IN ENGAGEMENT WITH SAID MATERIAL. 